Screw thread cleaning apparatus

ABSTRACT

Apparatus for cleaning screw threads, typically those in a pipe joint, including a plurality of arms pivotally connected to a shaft. Around the shaft is a sleeve having an internal rack portion in the vicinity of the shaft-to-arm connections, the arms having a mating pinion for swinging the arms outward to contact internal threads of the pipe when the shaft is axially moved inward with respect to the sleeve. Alternately, the arms can be swung out by centrifugal force when the shaft is rotated. The outward ends of the arms have free-wheeling, toothed cleaning wheels which meet the threads at an angle in the cleaning operation.

ilnited States Patent Rogers 5] Aug. 1, 1972 [54] SCREW THREAD CLEANING FOREIGN PATENTS OR APPLICATIONS APPARATUS 51,412 8/1918 Sweden ..15/104.13 [72] Inventor: John M. Rogers, PO. Box 777, Luling, Tex. 78648 Primary Examiner-Edward L. Roberts Attorney-Arnold, White and Durkee, Tom Arnold, [22] Flled May 1970 Robert A. White, Bill Durkee and Frank S. Vaden, ill [21] App1.No.: 39,669

[57] ABSTRACT 52 us. c1 ..15/104.14, 15/104.1s Apparatus for Cleaning Screw threads, yp y those 51 rm. (:1. ..B08b 9/02 in a p p joint, including a plurality of arms Pivotally 58 Field of Search ..15/104.01, 104.02, 104.03, Connected to a Shaft Around the Shaft is a sleeve 15/104 04 10405 10409 1041 10413 ing an internal rack portion in the vicinity of the shaft- 1O4 14 1045. 175/350 to-arm connections, the arms having a mating pinion for swinging the arms outward to contact internal [56] References Cited threads of the pipe when the shaft is axially moved inward with respect to the sleeve. Alternately, the arms UNITED STATES PATENTS can be swung out by centrifugal force when the shaft is rotated. The outward ends of the arms have free- 11 wheeling toothed cleaning wheels meet the 2 &2; i $3322 threads at an angle in the cleaning operation. 3:496,587 2/1970 Dowling ..l5/104.1 R 15 Claims, 5 Drawing Figures 28 50 42 I i 1 1 l l PRIME 40 MOVER l PATENTEDAus H972 3.680.167

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PATENTEDaus 1 m2 SHEEI 3 BF 3 m GPA v mil John M. Rogers INVENTOR llwd W/die, & 17mm ATTORNEYS SCREW THREAD CLEANING APPARATUS BACKGROUND OF THE INVENTION 1 Field of the Invention This invention relates to cleaning devices and more particularly to devices for cleaning the screw threads of Y tubular goods, such as pipe joints, tool joints, pipe couplings and the like.

2. Description of the Prior Art Internal threads of pipes, casings and the like become fouled by all manner of conditions. Some of these conditions include paint and other coatings, rust, ice, grease, and dirt. Even the presence of the slightest foreign matter interferes to some extent with smooth use of the threads. The presence of substantial quantities of foreign matter may prevent the threads from functioning altogether.

Many techniques have been employed in the past to clean threads. Three of the most widely used techniques employed in the cleaning of threads in pipe joints are wire brushes, hair brushes and steam. The disadvantages of each are substantial. Wire brushes usually span two or more teeth and even when substantial pressure is applied to the brush, the bristles often fail to do an adequate job of cleaning the valleys. Hair brushes, on the other hand, are often too soft, and the bristles fold back. As a result, there is often a lack of penetration and a resultant unsatisfactory cleaning. Also, hair brushes wear out rapidly. Steam cleaning is primarily effective against grease and ice, but does not scrape out rust and coating build-ups. Moreover, steam rises and does not do a thorough cleaning job on all sides.

SUMMARY OF THE INVENTION The cleaning apparatus for cleaning internal threads of a typical pipe joint presented herein, includes in a preferred embodiment a plurality of evenly spaced pivoted arms connected to a shaft, the shaft intended for axial movement along the center line of the pipe to be cleaned. On the end of each arm is a toothed wheel mounted for free rotation about a .pin. The arms are outwardly swingable to bring the wheels into an angular contact with the threads to be cleaned. This outward swing may be effected by centrifugal force or by a rack and pinion connector between the pivoted arm and the shaft. That is, the connection pushes the arm outward upon relative movement between the shaft and a sleeve, the arm having a pinion gear formed therein and the sleeve having a rack gear formed therein. Rotation of the shaft, such as by a power unit used in operating a hand drill, causes the threads to be cleaned by the cleaning wheels. These cleaning wheels do not bind, but are caused to rotate by a free-wheeling action, such rotation contributing to the cleaning operation.

Therefore, a feature of the present invention is to provide improved mechanical means that is useful in cleaning the valleys of threads.

Another feature of the present invention is to provide improved mechanical means employing a rotatable wheel with cleaning teeth thereon which will not bind on internal threads during relative cleaning movement.

Yet another feature of the present invention is to provide improved expandable mechanical means for cleaning internal pipe threads, such means being BRIEF DESCRIPTION OF THE DRAWINGS So that the manner in which the above-recited features, advantages and objects of the invention, as well as others which will become apparent, are attained and can be understood in detail, more particular description of the invention briefly summarized above may be had by reference to the embodiments thereof which are illustrated in the appended drawings, which drawings form a part of this specification. It is to be noted, however, that the appended drawings illustrate only typical embodiments of the invention and are therefore not to be considered limiting of its scope, for the invention may admit to other equally effective embodiments.

IN THE DRAWINGS FIG. 1 is a lateral cross-sectional view of one embodiment of the current invention.

FIG. 2 is a transverse cross-sectional view taken at 2-2 of FIG. 1.

FIG. 3 is a lateral cross-sectional view of another embodiment of the current invention.

FIG. 4 is a lateral cross-sectional view of the embodiment of FIG. 3, showing the arms of the apparatus-in a retracted position.

FIG. 5 is an alternate embodiment of the wheel structure of the invention.

DESCRIPTION OF PREFERRED EMBODIMENTS The word thread as used herein means screw threads and other configurations, such as gear teeth, that possess the characteristic of having valleys and/or peaks with respect to a surface.

Referring now to the drawings and first to FIG. 1, a section of pipe joint having arcuate internal threads 12 to be cleaned is shown. Apparatus for accomplishing this purpose is mounted with respect to a shaft 14, which, when in its position of use, is aligned axially in the center of the'longitudinal axis of pipe joint section 10.

Secured to one end of shaft 14 is spider block 16, typically by being screwed onto shaft threads 18. As may be seen in FIG. 2, the spider block is shaped to accept the connection of three pivot arms 20, although additional arms may be employed, if desired. Each of openings 22 in block 16 permits an arm 20 to be inserted therein so as to be radially movable or expandable in a plane which intersects the center line of axis 14.

'Each of arms 20 is secured in its opening by a pin 24.

The pin hasan enlarged head on one end for mating with a shoulder on block 16 to limit its axial movement and a receiving screw hole on the other to accept Allen head screw 26 to connect pin 24 to block 16.

A hole near the end of arm 20 accepts a threaded bolt 28 transverse to the longitudinal dimension of arm 20. A stand-off or sleeve 30 about bolt 28 spaces the head of the bolt away from the arm. Around the sleeve are located wheel 32 extending beyond the longitudinal limits of arm 20 and washers 34 and 36 located on either side thereof. There is a little clearance or space between the washers and the wheel such that wheel 32 is permitted to freely rotate. It should be noted that wheel 32 is carried in a plane which does not pass through the center line of shaft 14, but is off center thereto.

Referring again to FIG. 1, it may be seen that each of the wheels 32 has an outer periphery which is comprised of relatively sharp teeth 38. The teeth are sufficiently deep and sufficient sharp so as to be able to extend into the full valley of the screw thread to be cleaned. This is best illustrated by observing the teeth on the lower wheel in FIG. 1. Also, a Rockwell hardness of 39 has been found to be suited for the teeth of such wheel.

Around shaft 14 is a tubular sleeve 40. A head 42 surrounding block 16 is screwed onto sleeve 40 by external screw threads in a reduced shoulder portion 44. Shaft 14 passes through a hole 45 in the center of head 42.

Near the opposite end of sleeve 40 from head 42 is secured bearing 46, again leaving a center opening for centering shaft 14 within sleeve 40. Stop block 48 is secured to shaft 14 by Allen head screw 50 at a position which prevents shaft 14 from being removable from the sleeve, but which allows arms to extend to their position of use.

In operation of the apparatus shown in FIG. I, an external power source or prime mover 50, typically a power unit used in hand drilling or the like, is secured to shaft 14. Such a power unit normally employs a chuck for grasping the shaft. The revolution of the shaft is brought up to speed, typically on the order of 200 revolutions per minute. The speed of rotation of shaft 14 causes the arms to swing outwardly from pin connections 24, the weight distribution of the wheels on the arms causing this to happen. As may also be seen, the arms are adjustable for a wide range of internal diameter pipe sizes. If the unit is held in the approximate center of the arcuate threads to be cleaned, then the threads are contacted with approximately equal pressure by the teeth in each of wheels 38. Because the wheels are mounted off center with respect to the center line of shaft 14, the wheels meet the threads atan acute angle, this angle being sufficient to cause the wheels to turn or rotate freely about their mounting bolts 28 to facilitate cleaning.

Another embodiment of the invention is illustrated in FIGS. 3 and 4. In these drawings parts which are similar to the embodiment of FIG. 1 are similarly numbered. Head 42, however, in its larger dimension about block l6,'is internally threaded to form a gear rack section 52. A mating pinion gear 54 is formed in each of arms 20 concentric about pin 24. Otherwise, the embodiments of FIG. '1 and FIG. 3 are substantially identical.

As may be best shown in FIG. 4, shaft 14 is moved axially rearward in direction 56 with respect to sleeve 40 as the apparatus is inserted into the pipe joint section to be cleaned. This movement causes arms 20 to be held radially inward in direction 58, pinion 54 rotation in rack 52 causing this action to occur. In operation of this embodiment, the wheels of the apparatus are inserted into the pipe joint opposite the arcuate internal threads and the shaft is moved forward with respect to sleeve 14. The rack and pinion action causes the arms 20 to swing radially outwardly until the teeth of the wheels bear against the surface of the threads. Power is then applied to shaft 14 to effect cleaning, as before. Actually, the application of rotating power to the shaft automatically causes the arms to swing outward by centrifugal force. Further, shaft rotating during cleaning maintains pressure of the cleaning wheels against the screw threads, again by centrifugal force.

The embodiment of FIGS. 3 and 4 has an advantage over the embodiment shown in FIG. 1 in that pressure may more positively be brought to bear against the threads to be cleaned and the radial expansion of the arm and wheel assembly is uniform with respect to the shaft such as to center the entire apparatus and make for less chatter and vibration in the cleaning operation.

Although the teeth of the wheels have heretofore been described as pointed, such wheels are of course more susceptible to chipping and breakage than teeth which are somewhat rounded. Rounded teeth, such as shown in FIG. 5, may be used, so long as the dimension of the teeth are compatible with the thread dimension to be cleaned and the material which is to be cleaned away.

Although what has been illustrated and described has been apparatus primarily useful for cleaning threads which are arcuately disposed internal to a pipe, external thread cleaning may be similar accomplished. In using the apparatus as illustrated in FIG. 3 for such purpose, shaft 14 would be moved to the right relative to sleeve 40 to radially swing arms 20 away from shaft 14. The threads would then be inserted and the wheels brought inward to bear against the threads by axially moving the shaft in the opposite direction. An elbow in each of arms 20 may be formed to advantageously allow the arms to extend further onto the pipe to clean external threads for a greater distance.

The apparatus that has been described may typically be used to clean the threads of drill pipe joints used in oil well drilling which are returned to the yard of the rental tool agency at the completion of one job to prepare the pipe for the next job requirement. Such apparatus may also be employed at the well head to clean the box and/or pin of adjacent joints as they are assembled and lowered into the hole. Of course, the apparatus is not limited to any such use but is universally adaptable to almost any thread cleaning requirement.

While particular embodiments of the invention have been shown and described, it will be understood that the invention is not limited thereto, since many modifications may be made and will become apparent to those skilled in the art.

What is claimed is:

1. Apparatus for cleaning arcuate threads, comprismg:

radial adjustable means adapted to be rotated,

a plurality of wheels, each pivotally connected to said radial adjustable means, the plane defined by each of said wheels and the axis of each of said wheels being offset from the axis of rotation of said radial adjustable means, and each of said wheels having teeth in its outer periphery for rotary, nonbinding, angular engagement with the threads upon rotation of said radial adjustable means to effect cleaning, and

prime mover for rotating said radial adjustable means to cause said wheels to bear upon the threads by centrifugal force.

2. Apparatus for cleaning arcuate threads, comprising:

a shaft adapted to be rotated about its axis,

a block secured to one end of said shaft,

a plurality of arms connected to said block for relative radial movements,

a wheel having teeth in its periphery pivotally connected at the outer end of each of said arms for rotary, non-binding, angular engagement with internal threads to be cleaned when said shaft is rotated, the plane defined by said wheel and the axis of said wheel being offset from the axis of said shaft, and

a prime mover for axially rotating said shaft to radially move said arms, causing said wheels to bear upon the threads by centrifugal force.

3. Apparatus for cleaning arcuate internal threads,

comprising: radial expansion means adapted to be rotated,

a plurality of wheels, each pivotally connected to said expansion means and each of said wheels having teeth in its outer periphery for rotary, nonbinding, angular engagement with the internal threads upon rotation and expansion of said expansion means to effect cleaning, the plane defined by each of said wheels and the axis of each of said wheels being offset from the axis of said radial expansion means, and prime mover for rotating said radial expansion means to cause expansion thereof by centrifugal force.

4. Apparatus in accordance with claim 3 wherein said wheels are spaced substantially uniformly about said expansion means.

5. Apparatus for cleaning arcuate internal threads,

comprising:

at least one wheel having teeth in its periphery,

an arm pivotally connected to said wheel, and

means for centrifugally positioning said wheel against the internal threads at an acute angle such that upon arcuate movement of said wheel with respect to the internal threads said wheel rotates in non-binding engagement with the threads.

6. Apparatus for cleaning internal threads, comprisa shaft adapted to be rotated about its axis,

a block secured to one end of said shaft,

a plurality of arms connected to said block for outward pivotal movement therefrom,

a wheel having teeht in its periphery pivotally connected at the outer end of each of said arms for rotary, non-binding, angular engagement with the internal threads to be cleaned when said shaft is axially rotated, the plane defined by said wheel and the axis of said wheel being offset from the axis of said shaft, and

a prime mover for axially rotating said shaft to outwardly pivot said arms therefrom by centrifugal force.

7. Apparatus in accordance with claim 6, wherein said arms are spaced substantially uniformly about said 5 block.

8. Apparatus in accordance with claim 6, wherein the mass of said wheel causes the arm to which it is connected to pivot outwardly by centrifugal force when said shaft is rotated causing said wheel to bear against 10 th internal thre ds.

9. Apparatus for cleaning threads, comprising:

a shaft adapted to be rotated about its axis,

a block secured to one end of said shaft,

a tubular, internal gear rack about said block, and

a plurality of arms connected to said block for pivotal movement with respect thereto, each of said arms having:

a wheel having teeth in its periphery pivotally connected at the outer end of said arm for engagement with the threads to be cleaned when said shaft is axially rotated, and

external gear teeth concentric with the pivotal connection joining said arm and said block for mating with said rack, axial movement of said shaft with respect to said rack causing said gear teeth to operate in said rack to move said arms pivotally with respect to said block.

10. Apparatus in accordance with claim 9 wherein each of said arms moves pivotally outwardly by the same amount to center the apparatus within internal threads.

11. Apparatus in accordance with claim 9 and including a tubular sleeve, a portion of which includes said internal gear rack, said sleeve providing holding means for moving said shaft axially with respectto said rack.

12. Apparatus in accordance with claim 11 wherein each of said arms moves pivotally outwardly by the same amount to center the apparatus within internal threads.

13. Apparatus in accordance with claim 12, and including bearing means within said sleeve located about said shaft to facilitate alignment of the apparatus in the internal threads.

14. Apparatus in accordance with claim 9 wherein the plane defined by each of said wheels and the axis of each of said wheels are offset with respect to the axis of the shaft, so that said wheels meet said threads in rotary, non-binding, angular engagement.

13. Apparatus in accordance with claim 12, and including bearing means within said sleeve located about said shaft to facilitate alignment of the apparatus in the internal threads.

15. Apparatus in accordance with claim 9 wherein each of said arms moves pivotally inwardly by the same amount to center said shaft with respect to external threads. 

1. Apparatus for cleaning arcuate threads, comprising: radial adjustable means adapted to be rotated, a plurality of wheels, each pivotally connected to said radial adjustable means, the plane defined by each of said wheels and the axis of each of said wheels being offset from the axis of rotation of said radial adjustable means, and each of said wheels having teeth in its outer periphery for rotary, nonbinding, angular engagement with the threads upon rotation of said radial adjustable means to effect cleaning, and a prime mover for rotating said radial adjustable means to cause said wheels to bear upon the threads by centrifugal force.
 2. Apparatus for cleaning arcuate threads, comprising: a shaft adapted to be rotated about its axis, a block secured to one end of said shaft, a plurality of arms connected to said block for relative radial movements, a wheel having teeth in its periphery pivotally connected at the outer end of each of said arms for rotary, non-binding, angular engagement with internal threads to be cleaned when said shaft is rotated, the plane defined by said wheel and the axis of said wheel being offset from the axis of said shaft, and a prime mover for axially rotating said shaft to radially move said arms, causing said wheels to bear upon the threads by centrifugal force.
 3. Apparatus for cleaning arcuate internal threads, comprising: radial expansion means adapted to be rotated, a plurality of wheels, each pivotally connected to said expansion means and each of said wheels having teeth in its outer periphery for rotary, non-binding, angular engagement with the internal threads upon rotation and expansion of said expansion means to effect cleaning, the plane defined by each of said wheels and the axis of each of said wheels being offset from the axis of said radial expansion means, and a prime mover for rotating said radial expansion means to cause expansion thereof by centrifugal force.
 4. Apparatus in accordance with claim 3 wherein said wheels are spaced substantially uniformly about said expansion means.
 5. Apparatus for cleaning arcuate internal threads, comprising: at least one wheel having teeth in its periphery, an arm pivotally connected to said wheel, and means for centrifugally positioning said wheel against the internal threads at an acute angle such that upon arcuate movement of said wheel with respect to the internal threads said wheel rotates in non-binding engagement with the threads.
 6. Apparatus for cleaning internal threads, comprising: a shaft adapted to be rotated about its axis, a block secured to one end of said shaft, a plurality of arms connected to said block for outward pivotal movement therefrom, a wheel having teeht in its periphery pivotally connected at the outer end of each of said arms for rotary, non-binding, angular engagement with the internal threads to be cleaned when said shaft is axially rotated, the plane defined by said wheel and the axis of said wheel being offset from the axis of said shaft, and a prime mover for axially rotating said shaft to outwardly pivot said arms therefrom by centrifugal force.
 7. Apparatus in accordance with claim 6, wherein said arms are spaced substantially uniformly about said block.
 8. Apparatus in accordance with claim 6, wherein the mass of said wheel causes the arm to which it is connected to pivot outwardly by centrifugal force when said shaft is rotated causing said wheel to bear against the internal threads.
 9. Apparatus for cleaning threads, comprising: a shaft adapted to be rotated about its axis, a block secured to one end of said shaft, a tubular, internal gear rack about said block, and a plurality of arms connected to said block for pivotal movement with respect thereto, each of said arms having: a wheel having teeth in its periphery pivotally connected at the outer end of said arm for engagement with the threads to be cleaned when said shaft is axially rotated, and external gear teeth concentric with the pivotal connection joining said arm and said block for mating with said rack, axial movement of said shaft with respect to said rack causing said gear teeth to operate in said rack to move said arms pivotally with respect to said block.
 10. Apparatus in accordance with claim 9 wherein each of said arms moves pivotally outwardly by the same amount to center the apparatus within internal threads.
 11. Apparatus in accordance with claim 9 and including a tubular sleeve, a portion of which includes said internal gear rack, said sleeve providing holding means for moving said shaft axially with respect to said rack.
 12. Apparatus in accordance with claim 11 wherein each of said arms moves pivotally outwardly by the same amount to center the apparatus within internal threads.
 13. Apparatus in accordance with claim 12, and including bearing means within said sleeve located about said shaft to facilitate alignment of the apparatus in the internal threads.
 13. Apparatus in accordance with claim 12, and including bearing means within said sleeve located about said shaft to facilitate alignment of the apparatus in the internal threads.
 14. Apparatus in accordance with claim 9 wherein the plane defined by each of said wheels and the axis of each of said wheels are offset with respect to the axis of the shaft, so that said wheels meet said threads in rotary, non-binding, angular engagement.
 15. Apparatus in accordance with claim 9 wherein each of said arms moves pivotally inwardly by the same amount to center said shaft with respect to external threads. 